1. Field Of The Invention
The present invention relates to torquing systems. More particularly, the present invention relates to an improved torque wrench system which provides for the makeup and removal of threaded bolts with a single tool during both high torque and low torque phases of the makeup or removal process.
2. General Background
In the makeup or break down of large structures, such as, for example rig risers, the sections of the riser are flanged together with bolts threadedly engaged to flanges on the end of each section, and made up very tightly to complete the structure. Of course, there are numerous other types of structures which utilize this same system of makeup, utilizing very large bolts to flange together sections of the structure.
When this type of makeup system is utilized, there is usually required at least two tools in the makeup. First, a high speed, low torque motor or wrench is utilized to begin the threading of the bolt into the flange. However, as the bolt is tightened, it requires a very high amount of torque, in the neighborhood of 40 thousand ft. lbs. in order to complete the makeup. Therefore, a second tool, such as a hydraulic ratchet, is utilized, which imparts a very high torque to the bolt, and completes the makeup procedure. Of course, when the bolts must be removed, the high torque wrench would be utilized to commence the removal of the bolt, and then, to increase the speed of removal, a high speed low torque motor or the like would be engaged. This two step process is very time-consuming, and inefficient. However, up to now, this was the state of the art in the makeup and removal of such bolts from structures.
There were several patents found in the art which address the subject matter of torque applied to bolts, or the like, and these are referred to in the Prior Art statement submitted concurrently herewith.
The system of the present invention solves the shortcomings in the art in a simple and straightforward manner. What is provided is an improved system for installing and removing bolts from flanged joints or the like which includes a primary wrench for engaging the head of the bolt and rotating the bolt during the high-torque phase, a low-torque motor engaged with the wrench for rotating the bolt during the low-torque phase of removal or installation; a source of fluid for driving the low-torque motor during the low-torque phase, and driving the high-torque wrench during the high-torque phase; and valving means for sensing the high-torque and low-torque phases, in order to drive the hydraulic wrench or the motor depending on the torque required.
Therefore, it is a principal object of the present invention to provide a combination high-torque, low-torque system for installing or removing bolts or the like from structures;
It is a further object of the present invention to provide a system for removing bolts from flanged structures with a single combination tool which works under both low-torque or high-torque conditions, depending on the condition sensed by the system;
It is a further object of the present invention to provide a system for removing or installing bolts having a very low clearance and normally inaccessible to wrenches having both high speed low torque and low speed high torque capacities.